Analog to digital converters (ADCs) are employed in a wide variety of applications. For example, ADCs are often used in audio recording equipment to convert analog audio signals into digital signals that can be stored on digital media. Also, ADCs are usually employed to convert a received wireless (analog) signal into a digital signal for further processing by other components in a mobile device.
For wireless communication, the amount of resolution (number of bits) and/or sampling frequency for an ADC to actually process a wireless (analog) signal can vary widely based on a variety of circumstances. For example, if a mobile device is operating in a monitor mode (waiting to receive a wireless signal addressed to the mobile device), the resolution and sampling frequency employed by the ADC can be relatively low. In contrast, during voice communication between mobile devices over a relatively long distance, an ADC might need to employ a relatively high sampling frequency and resolution to ensure that the voice data is communicated in real time.
Typically, the resolution and sampling frequency values of an ADC for a mobile device are set at least as high as the highest values necessary to process the most complex wireless communication such as voice communication over a relatively long distance. Unfortunately, these higher values typically cause the ADC to consume more power than necessary for much of the time that the mobile device is monitoring wireless signals in a standby mode. In the past, ADCs have not been able to dynamically adapt their resolution and/or sampling frequencies to the minimum values necessary to support different types of wireless communication modes and protocols over differing distances.